Mailbox migration times out when going from Exchange OnPrem to O365

ISSUE: When attempting to migrate an onPrem User mailbox from Exchange 2013 to O365, the following error is generated and the migration fails: The request channel timed out while waiting for a reply after 00:00:00.0012345. Increase the timeout value passed to the call to Request or increase the SendTimeout value on the Binding. The time…


Mail not routing to on-premise Exchange 2013 environment from O365 with 450 4.7.320 Certificate validation failed error

Issue: User is trying to send email from his O365 Tenant in to the OnPrem Exchange 2013 environment. The email fails with the following reason (as seen in the message tracking logs in O365: Reason: [{LED=450 4.7.320 Certificate validation failed};{MSG=SubjectMismatch};{};{IP=###.###.###.###};{LRT=4/14/2017 1:07:17 PM}]. OutboundProxyTargetIP: ###.###.###.###. OutboundProxyTargetHostName: Cause: We found that the certificate it was trying…


O365 Migration that completes with warnings due to insufficient rights.

The Problem: With the rise in Hybrid configurations around the world, we are starting to see some regular occurrences of issues around migrating from OnPremises exchange (called OnPrem henceforth) to O365. Perhaps the most common is one where most users migrate fine, but a select few only partially migrate. When you look at the migration logs, they…

Only seeing first receive event when doing message tracking against a public folder that was migrated to O365 from Legacy Exchange

In Exchange 2010 and older (legacy exchange), when you migrate a public folder to O365, it makes a change that causes message tracking to only show the initial receive event when running message tracking against the legacy namespace. Scenario A Public Folder with a Primary SMTP email address of gets migrated to O365. You…


Unable to expand legacy onPrem Public Folders with O365 account

I have been seeing a few scenarios lately where users who log into Exchange using an account other than the OnPrem User Principal Name (UPN) are running into various difficulties. Today we will focus on one of those scenarios. We will discuss how we figured it out and what needs to be done to get the desired functionality….